Black veins: a case of minocycline‐induced pigmentation post‐sclerotherapy and a review of literature

Abstract

Minocycline-induced pigmentation (MIP) is an uncommon but well-described adverse effect of oral minocycline treatment. MIP is clinically and histopathologically distinct from post-sclerotherapy pigmentation. We report a case of a patient presenting with blackened skin overlying veins recently treated with endovenous laser and foam sclerotherapy. The patient was a 44-year-old male with systemic sclerosis who commenced minocycline for the treatment of rosacea 5 months prior. Histological examination of the discolored tissue and underlying vein revealed hemosiderin deposition in the dermis and pigmented macrophages within the sub-endothelial layer of the vein wall with a staining pattern consistent with MIP. Venous tissue has not previously been reported in the literature as a target of minocycline pigmentation. Our patient preferred to control his rosacea by continuing to take minocycline. Follow-up ultrasound examinations revealed the treated vessels to be fully occluded with no evidence of recanalization, residual flow or ongoing thrombophlebitis. Despite a good sclerotherapy outcome, the pigmentation did not subside over 2 years. This case demonstrates that oral minocycline may induce significant and potentially long-term pigmentation in predisposed patients undergoing sclerotherapy.

Pigmentation of lower limbs: Contribution of haemosiderin and melanin in chronic venous insufficiency and related disorders

“…Skin colour and the associated Fitzpatrick skin type is genetically determined by the quantity of melanin within melanosomes and the concentration of melanosomes within keratinocytes. 14 Inflammation, UV radiation, systemic conditions such as Addison’s disease 15 and drugs such as minocycline 16 or clofazimine can upregulate the melanogenesis pathway resulting in skin darkening. Autoimmune conditions such as vitiligo can result in downregulation of melanogenesis due to the autoimmune destruction of melanocytes, leading to de-pigmentation or hypopigmentation.…”

Sclerotherapy of lower limb veins: Indications, contraindications and treatment strategies to prevent complications – A consensus document of the International Union of Phlebology-2023

“…(ii) Minocycline The concomitant intake of minocycline while undergoing sclerotherapy has been reported to result in skin hyperpigmentation in several case reports. [225][226][227][228] Minocycline is a member of the tetracycline family of antibiotics used to treat acne and is frequently taken for years. Unlike typical pigmentation that may be seen after sclerotherapy, minocycline-induced PSP is slategrey to blue-black and is due to perivascular deposition of iron complexes of haemosiderin and minocycline moieties.…”